We are requesting a Siemans Dual 37 Rota Gamma Camera System to enable us to detect defined regions of specific organs without the complications of underlying activity. In particular, the increased resolution and contrast will be possible in the brain and heart using muscarinic-cholinergic, receptor-binding radiotracers. In the antibody labeling project, it is very important to detect small tumors and again increased resolution and contrast will benefit this effort. The gamma camera is also requested to do Tc-99m MAA lung perfusion studies and 123I iodo-amphetamine brain perfusion studies on large numbers of animals. The longitudinal studies require repeat scans every three months, necessitating a dedicated research camera. This imaging device would allow us to do repeat experiments and studies without having to sacrifice animals and will allow animals to serve as their own controls thereby improving the statistical significance of the studies. No such imaging device is available to us for the amount of time we require to do the existing project, and the proposed projects cannot be considered without this new system.